class_docstr: Lightweight immutable Dataframe similar to Pandas Dataframe.
code: def __add__(self, other: "DataFrame") -> "DataFrame":
      if not set(self.column_names).intersection(
          other.column_names
      ) and len(self.rows) == len(other.rows):
          return DataFrame(
              column_names=list(
                  itertools.chain(self.column_names, other.column_names)
              ),
              columns=list(
                  itertools.chain(self.columns, other.columns)
              ),
          )
      if self.column_names == other.column_names:
          return DataFrame(
              column_names=self.column_names,
              rows=list(itertools.chain(self.rows, other.rows)),
          )
      raise ValueError("Cannot combine two DataFrame")
  
imports: import itertools
  import json
  from typing import Any, Callable, Optional, Sequence, Tuple, Union
  from collections import namedtuple
  import numpy
  from tensorflow.python.compiler.tensorrt.model_tests import model_handler
  import tensorflow.python.compiler.tensorrt.trt_convert
  from tensorflow.python.platform import tf_logging
label_desc: Use image node_id 7 for calling the DataFrame obj's underlying member method code with example usage: obj.__add__(other) and returns: DataFrame, DataFrame